11 November 2011

11/11/11 (a.k.a. 11-11-11); Friday, November 11, 2011: Mathematics

 The number eleven is the fifth prime number (contrary to popular belief, the number one ( 1 ) is not a prime number).

The base numeric number system lends itself to some interesting peculiarities as relates to the number eleven.

Base 10 for example:
(2 digits) 11 x 11 = 121
(6 digits) 111111 x 111111 = 12345654321
(9 digits) 111111111 x 111111111 = 12345678987654321

Base 16 (hexadecimal) for example:
(2 digits) 11 x 11 = 121
(6 digits) 111111 x 111111 = 12345654321
(9 digits) 111111111 x 111111111 = 12345678987654321